Checking device



L. J. GARAY v. 2,543,492

CHECKING DEVIQ'IFY 3 Sheets-Sheet 1 lnz/enzar Lazls J 6am Feb. 27, 1951 Filed Jan. 10, 1947 L. J.' GARAY V.

Feb. 27, 1951 CHECKING DEVICE 3 Sheets-Sheet 2 Filed Jan. 10, 1947 ji'z ezzzo Luis J 6% V Feb. 27, 1951 J. GARAY v. 2,543,492

CHECKING DEVICE Filed Jan. 10, 1947 s Sheets-Sheet 3 [WQ/Zfij 1 415 J @amy V Patented F e1). 27, 1951 UNITED STATES PATENT OFFHCE 2 Claims.

The present invention relates to improvements in instruments for checking the dimensions and concentricity of cutting tools and other machined parts, and has specific reference to a checking device adapted for checking the eccentricity and the location of the cutting edges of single or multiple edged tools with respect to a fixed reference point.

One of the objects of the invention is to provide a checking device of the foregoing character which is adaptable for use with a large variety of cutting tools and which is capable of ready, accurate and convenient manipulation.

Another object is to provide a checking device which is rugged, compact and inexpensive in construction and which is accurate and reliable in use. I

Other objects and advantages will become apparent as the description proceeds.

In the accompanying drawings,

Figure 1 is a front elevational view of a checking device embodying the features of the invention.

Fig. 2 is a plan View of the device.

Fig. 3 is a right end view of the device.

Fig. 4 is a fragmentary transverse sectional view of the work fixture taken substantially along lines 4-4 of Fig. 2.

Fig. 5 is a fragmentary plan view of the work fixture and illustrating one means for locating a block type boring cutter in centered position.

Fig. 6 is a fragmentary side elevational view of the structure illustrated in Fig. 5.

Figs. '7, 8 and 9 are fragmentary'vertical sectional views of one of the checking fixtures taken respectively along lines '!1, 88 and 9-9 of Fig. 2.

Fig. 10 is a fragmentary bottom view of the means for guiding and clamping the checking fixture.

Fig. 11 is a fragmentary side elevational view A work fixture 3 is mounted on the plate I for supporting alternatively a master gauge member or the part to be checked thereagainst, and is provided with means for accurately locating and supporting either the member or the work part in symmetrical or centered relation to the zero reference point of the scale 2. Suitable checking fixtures 4 and 5 are mounted on the plate i respectively at opposite sides of the work fixture 3 for independent longitudinal adjustment along the scale 2 into opposed positions predetermined by the dimensions of the master gauge member, and are adapted to support respectively two appropriate measuring elements,

15 such for example as dial indicators with actuating stems or buttons 1 for contacting the work surfaces to be checked. The indicator stems 1 are arranged to extend longitudinally of the scale I, and are independently axially adjustable within their supporting fixtures t and 5, so that they may be located, while in contact with the opposite ends of the master gauge member, and providing the fixtures are correctly positioned in relation to the zero reference point, to set the indicators 6 for zero readings. The work fixture 3 and the indicators 5 are also selectively adjustable in mutually perpendicular directions transversely of the plate, I in order to secure the desired alignment between the stems and the work surfaces to be contacted.

Considering now the detailed construction of the checking device, the base plate I is preferably fiat and rectangular in shape, and is formed with two spaced aligned longitudinal guide slots 8 in opposite end portions respectively for supporting the checking fixtures 2 and The scale 2 is formed on a metal strip 9 set and secured as an insert within a longitudinal notch i i] in the upper front edge of the plate :1, and may comprise graduations of any suitable units of measurement, such as inches and sub-divisions thereof.

Ihe work fixture 3 is provided to locate and support the part to be measured or to be checked against a standard, in accurately centered relation to the zero reference point of the scale 2, and hence may be varied in construction depending on the character of the measurements to be made. Although not limited to the measurement of any particular type of work part, the checking device, in general, is especially adapted for checking either a single dimension or several dimensions bearing some definite relation to a fixed central point or axis, and is specifically disclosed 3 in a form adapted for checking the opposed cutting edges of a block type boring tool II. More particularly, the tool ll, as shown, comprises a fiat elongated bar 12 having inserted blade cutters i3 symmetrically clamped in opposite ends, and formed centrally thereof with a locating slot i i. In use, the bar i2 is inserted through a slot in a boring bar (not shown), is located in central position by a key engaging in the slot 14 so that both cutters will have the same circle of revolution, and is clamped in position by a taper screw engaging in a tapered hole 15. To support the tool Ii rigidly in centered position between the checking fixtures and 5, and in reference to the zero point of the scale 2, the work fixture 3 preferably comprises an upstanding base or pedestal l5 rigid with the top of the base plate I and formed with horizontal transverse guides H. A tool or work supporting slide 18 is confined on the pedestal :6 in sliding engagement with the guides ii for adjustment transversely of the base plate I.

Any suitable means may be provided for adjusting the slide 18 and securing it in selected position of adjustment. In the present instance, a nut is is secured to the underside of the slide [8 and extends downwardly through a transverse slot 28 in the pedestal 15. An adjusting screw journalled in the rear portion of the pedestal iii extends longitudinally into the slot 26, and is in threaded engagement with the nut i9. The screw BI is constrained against endwise movement by a peripheral spline Z2, and is provided at its outer end with an adjusting knob 23. An axial threaded stud 24 on the lower end of the nut It extends into a transverse V-shaped slot 25 in the base plate I, and is engaged by a clamp nut 28 having a rearwardly projecting operating handle 2?. Swinging movement of the handle 21 within the slot or clearance 25 will either release the nut 25 to permit adjustment of the slide ill, or will tighten the nut against the lower surface of the pedestal IS to secure the slide in position of adjustment.

The slide i8 is provided with means for locating and clamping the tool H in the same central or symmetrical position with reference to the zero point of the scale 2 that the tool would occupy when mounted in the boring bar. Thus, the top of the slide I8 is flat, and formed in the top with a tapered opening 28 adapted for registration with the opening l5 in the tool II. The tool H may be quickly and accurately positioned on the slide [3 by means of a locating lock or bar 25 aligned by a key 38 and centered by dowel pins 3|. The bar 29 has a straight edge 32 parallel to the guide slots 8, and a key 33 is inserted in this edge for engaging in the slot i l in the tool H. The dowels 3i and the key 33 are so located that the latter will be located accurately on center with the zero reference point of the scale 2. Corn sequently, when the tool I l is located against the edge 32, with the key 33 inserted in the slot i l, it also will be accurately centered. To secure the tool H against the edge 32, a tapered screw 34, with a hand knob 35, is inserted through the hole l5 into the hole 28, and threaded into a tapped hole 35 at the bottom of the latter. The screw 3G bears hard against the side of the hole 55 adjacent the edge 32 to insure tight contact of the tool bar I2 against the bar 29. It will be understood that different types and sizes of locating bars may be substituted as required to suit dif-- ferent kinds of cutter bars. In some instances, it may be expedient to dispense with the locating 4 bar 29, and rely solely on the tapered screw 34 to centralize the tool bar.

The checking fixtures 4 and 5 preferably are alike in construction, and hence a description of one will suifice for both, like parts of the two being identified by the same reference characters. Thus, each fixture comprises an upright frame or bracket 3'! movable on the base plate 1, and having a depending square-sided lug 33 slidably guided in the associated slot 8. Two spaced parallel cross plates 39 are attached to the bottom of the lug 38, and overlap the countersunk side edges of the slot 8 to confine the frame 3? adjustably in position. An adjusting screw 40, journalled in the outer end of the base plate I, extends longitudinally in the slot 8 and through threaded engagement with the lug 38. The screw is constrained against endwise movement by a peripheral spline 4|, and is provided at the outer end with a hand knob 42. To provide means for clamping the frame 31 in selected position of adjustment, a draw bolt 43 is rotatabl anchored therein at the upper end, and is threaded at the lower end into a clamp plate 44 disposed between the gib plates 39. In the preferred construction, the upper end of the bolt 43 is rotatably confined by a peripheral spline 45 in a cross plate 45 bridging the top of the frame 31, and is provided with a hand knob 41 to facilitate rotation.

The adjustment of each of the fixtures 6 and 5 is indicated by the scale 2, and is normally set to correspond to the desired dimension of the tool H from the zero reference point to the contiguous outer end surface to be checked. To insure accuracy of location, a Vernier 58 is attached to the front of each fixture frame 1' in cooperative relation to the scale 2, and the readings are reflected by an adjustable mirror 49 to an optical unit 55 for observation by the user of the checking device. The mirror 49 and unit 50 are suitably supported by arms 5| and 52 from the associated fixture frame 3'! for adjustment therewith.

The frame 3'! of each checking fixture is formed in the outer face with a fiat recess 53 defining spaced parallel vertical guideways 54 closed at the top by the cross plate 45. Slidably disposed within the recess 53, and confined within the guideways 54, for vertical adjustment is a biock or slide 55 supporting the dial indicator 5. A vertical adjusting screw 56, with a hand knob 51 on the upper end, is rotatably confined in the cross plate 45 by a spline 58, and extends downwardly through and in threaded engagement with a tapped hole 59 in the block 55, and then through an elongated vertical guide slot 66 in the latter. The extreme lower end of the screw 56 is reduced in diameter and journalled in a bore 65 in the base of the recess 53. It will be understood that the drawbolt 43 for clamping the frame 37 extends freely through a vertical bore 52 in the block 55. To provide means for clamping the block 55 in selected position of adjustment, 9. double-end screw stud 63 is anchored to the frame Si and extends into the slot 63. The stud 63 is apertured transversely to receive the adjusting screw 56. A knurled nut 513 is threaded on the outer end of the stud 63, and adapted to be tightened thereon against the block 55 to clamp the latter in position.

The dial indicator 6 is provided with a radial supporting sleeve 55 through which the actuating stem 7 extends, and which is adjustably secured by a set screw 66 in a bore 6? opening through the block 55 in a direction parallel to the scale 2. A vertical slot'68 opens from the inner face of the recess 53 through the frame 37 to receive the sleeve 65 and stem 1 and permit engagement of the latter with the adjacent end of the tool I i or other work part. The set screw 56 is accessible through a vertical tapped bore 69 from the top of the block 55. The dial indicator 6 per se forms no part of the present invention, and hence is not disclosed in detail. It is sufiicient to state that the indicator has a scale 16, with a zero pointbetween positive and negative graduations representing the same units of measurements as the scale 2, and that the stem 1 is normally spring-urged outwardly toward the work fixture 3.

In operation, the indicator setting is checked to insure that the position of the stem for zero reading will correspond with the zero point of the Vernier 48. This may conveniently be accomplished by the use of a master gauge member which is mounted on the work slide is in place of the tool H, and which has predetermined longitudinal dimensions subject to measurement from opposite sides of the zero reference point of the scale 2. Thus, assuming that the gauge member is four inches long, with a center slot or keyway engageable by the key 33, each of the checking fixtures l and 5 is adjusted along the scale 2 until the Vernier 48 indicates an accurate setting of two inches at each side. Each indicator 6, with its stem 1 in contact with the gauging surface of the gauge member, is now adjusted, if necessary, to register zero reading.

With the parts thus adjusted and clamped in position, the master gauge member is removed, and the boring cutter to be tested is mounted on the work fixture 3. The fixture slide 88 and the blocks 55 are of course adjusted as required to locate the stems or buttons '1 in proper alignment with the gauging surfaces of the blade cutters I3. Therefore, the indicators 6 will afford an accurate check of the radial dimension of each cutting edge with reference to the center keyway M and also of the concentricity of the edges; plus and minus deviations being indicated by positive and negative readings. The foregoing represents use of the checking devices as a comparator, without resetting, for tools of the same dimensions within a normal range of tolerances. It will be understood, however, that the device may also be employed to take direct measurements merely by adjusting either or both of the checking fixtures G and 5 to the dimensions of any given work part. Assuming that the indicators 6 remain properly correlated with the verniers d8, each measurement may be taken directly from the scale 2 if the related indicator registers zero, or computed from the sum of the readings if the indicator does not register zero.

The stationary type of work fixture 3, although suitable for determining concentricity and radial spacing of certain tool surfaces in one setting, does not permit of direct measurement of the actual cutting diameter of the edges of the tool li and is not adapted for the testing of cutting edges which are not substantially diametrically opposed. Figs. 11 and 12 illustrate a modified form of work fixture of the swivel type which is adapted for the measurement of cutting diameter and of acutely spaced radial dimensions. In this fixture, a slide te corresponding to the slide I3, is provided with upstanding end brackets ll respectively supporting a fixed center 72 and an axially-aligned retractible center 13. An arbor M is adapted to be supported endwise between the centers 72 and 13, and is cut away on one side to provide a side abutment 15 and a flat mounting surface 16 for the tool H. The surface 76 is of such depth that the transverse center line of the tool bar li will be coincident with the axis of rotation of the arbor "it. A clamping plate 71 is removably secured by a knurl-headed screw 58 to another flat surface 19 in stepped relation to the surface 76, and is formed with a locating key 33 for engaging in the slot M, and with a wedge flange 80 arranged for engagement with an inclined face 8! to clamp the tool bar i2 securely against the abutment 75. It will be evident that by rotary adjustment of the arbor M, the diametrically opposed edges of the cutters I 3 may be brought simultaneously and directly into gauging contact with the dial indicators 6 to check not only the concentricity but also the actual cutting diameter of the edges.

I claim as my invention:

1. A checking device for measuring external surfaces in relation to a zero reference point comprising, in combination, an elongated base plate formed with a longitudinally extending slot and a fixed transverse guide, a linear scale on the front longitudinal edge of said plate and having a zero reference point located centrally of said guide, a slide mounted for adjustment on said guid and adapted to support the part to be checked, means for locating and clamping said part on said slide in predetermined relation to said reference point, an upright frame slidably guided in said slot for adjustment along said scale member, said frame being formed with a vertical guideway, a block mounted for adjustment in said guideway, and a dial indicator supported on said block and having an actuating stem engageable with said part, said indicator being bodily adjustable on said block longitudinally of said scale member to permit of correlation therewith, said indicator having a scale for indicating positive and negative deviations in the spacing from said zero reference point a of the surface of said part being checked from a predetermined setting of the frame.

2. A checking device for measuring external surfaces in relation to a zero reference point comprising, in combination, an elongated base plate formed with a longitudinally extending slot and a fixed transverse guide, a scale member secured to the front longitudinal edge of said plate and having a zero reference point located centrally of said guide, a slide mounted for adjustment on said guide and adapted to support the part to be checked, means for adjusting said slide, means for clamping said slide in adjusted position, means for locating and clamping said part on said slide in predetermined relation to said reference point, an upright frame slidably guided in said slot for adjustment along said scale member, means for adjusting said frame, means for clamping said frame in adjusted positions, said frame being formed with a Vertical guideway, a block mounted for adjustment respectively in said guideway, means for adjusting said block, means for clamping said block in position, and a dial indicator supported on said block and having an actuating stem engageable with said part, said indicator being adjustable on said block longitudinally of said scale member to permit of correlation therewith, said indicator having a scale for indicating positive and negative deviations in the spacing from said 7 zero reference point of the surface of said part Number being checked from a predetermined setting of 1,554,646 the associated frame. 1,579,108 LUIS J. GARAY V. 2,136,134 5 2,359,018 REFERENCES CITED 2,421,953 The following references are of record in the 2495391 file 01" this patent:

UNITED STATES PATENTS m Number Number Name Date 413,780

1,474,992 Zuber Nov. 20, 1923 Name Date Olson Sept 22, 1925 Harter Mar. 30, 1926 Holley Nov. 8, 1938 Balk Sept. 26, 1944 McComb June 10, 1947 Davis Jan. 31, 1950 FOREIGN PATENTS Country Date England Oct. 31, 1934 

